Tony Parker sat out the Spurs' game against Atlanta on Saturday with a sore neck.
Nando De Colo, a 25-year-old rookie from France, is making his fifth start in place of Parker.
Parker left two minutes into the fourth quarter of San Antonio's 100-88 loss at the Oklahoma City Thunder on Thursday night after experiencing pain in his left shin. Spurs officials said his absence Saturday was due to his neck, however.
Parker is averaging 20.6 points, 7.5 assists and 2.5 turnovers in 33 minutes.
The 12-year veteran has missed 14 games this season, including eight from March 3 through March 20 with a Grade 2 left ankle sprain.
The Spurs are already without Manu Ginobili, who missed his fifth straight game after straining his right hamstring in the first quarter of San Antonio's 104-102 home victory over the Los Angeles Clippers on March 29.